Dispirited by a puncture in actual fact (8)
I believe the answer is:
deflated
'dispirited' is the definition.
Both the answer and definition are adjectives. Perhaps you can see an association between them that I don't see?
'a puncture in actual fact' is the wordplay.
'a puncture' becomes 'flat' (I've seen this before).
'in' means one lot of letters goes inside another.
'actual fact' becomes 'deed' (I am not sure about the 'actual' bit.).
'flat' placed into 'deed' is 'DEFLATED'.
'by' acts as a link.
Can you help me to learn more?
(Other definitions for deflated that I've seen before include "Let out air or gas from" , "Crestfallen" , "Depressed like punctured balloon" , "Collapsed by releasing air" , "Lost self-esteem - or gas?" .)